1. Field of the Invention
The present invention relates to light-emitting diodes (LEDs), and especially to an LED used in a backlight system for a device such as a liquid crystal display.
2. Description of the Prior Art
Liquid crystal displays are commonly used as the display device for compact electronic apparatuses, because they not only display good quality images using little power but also are very thin. However, the liquid crystals in a liquid crystal display do not emit any light themselves. The liquid crystals have to be lit up by a light source so as to clearly and sharply display text and images. Typically, LEDs are used as the light source because of their high luminance and low loss.
Referring to FIG. 5, a conventional LED I includes a base 16, a chip body 13 mounted on the base 16, and an encapsulation can 15 sealing the chip body 13. In general, the encapsulation can 15 is made of a transparent or translucent epoxy resin, and a maximum radiation angle of the LED 1 is 120°.
FIG. 6 shows a backlight system 90, comprising three of the LEDs 1 and a light guide plate 2. Light paths within the light guide plate 2 are also shown. Light beams 3 are projected from the LEDs 1 to an incident surface (not labeled) of the light guide plate 2. The light guide plate 2 redirects the light beams, which then emit from an emitting surface (not labeled) of the light guide plate. However, because each of the LEDs 1 emits light beams with a maximum radiation angle of 120°, resulting light beams 3 within the light guide plate 2 yield a plurality of dark areas 23 corresponding to gaps between adjacent LEDs 1. The dark areas 23 prevent the backlight system 90 from providing uniform illumination.
Therefore, it is desired to provide an LED and a backlight system using the same which overcome the above-described disadvantages of the prior art.